JP3028291B2 - Material supply device for injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material supply device for an injection molding machine having a feed screw for controlling a supply amount of a molding material supplied from a hopper into a heating cylinder.

[0002]

2. Description of the Related Art Conventionally, molding material stored in a hopper is
A material supply device of an injection molding machine in which a feed screw is supplied to the inside of a heating cylinder by a rotating feed screw is known, for example, from Japanese Utility Model Publication No. 52-35968.

In this type of material supply apparatus, a molding material (pellet) in a hopper is supplied to a material intake side of a horizontal material supply passage accommodating a feed screw, and the supplied molding material rotates. It is sent to the material discharge side of the material supply passage by the feed screw, and then falls into the heating cylinder. Therefore, the supply amount of the molding material to the heating cylinder is controlled by the rotation speed of the feed screw.

[0004] Incidentally, the pellet is a granular resin material having a size of about several millimeters. Therefore, in the case of a material supply device using a feed screw, pellets may bite between the feed screw and the material supply passage, and an excessive load may be applied to the rotation motor. A certain gap is provided between them to prevent the pellets from biting.

[0005] However, when an extender smaller than a pellet, for example, a spherical glass balloon or glass bead is used in this type of material supply device, the extender passes through a gap between the feed screw and the material supply passage. Therefore, since it directly flows into the inside of the heating cylinder, it becomes impossible to control the supply of such an expanding material.

In order to solve this problem, the present applicant arranges a regulating member at the front end of the material supply passage accommodating the feed screw, which regulates the amount of the molding material sent out from the feed screw. A material supply device for discharging a molding material from one or more holes (notches) provided in a member has already been disclosed in Japanese Patent Application Laid-Open No. 7-32911.
No. 4 proposed this.

[0007]

However, the material supply device disclosed in Japanese Patent Application Laid-Open No. Hei 7-329114 discharges the molding material from the hole located at the front end of the material supply passage. In addition, the amount of discharge from the lower hole increases, and even if the feed screw is stopped,
The amount of molding material supplied cannot be accurately controlled, for example, when the molding material spills from the lower hole, and even when a single hole is provided on the upper side, the flight portion of the feed screw and the hole Since the molding material is temporarily accumulated in the space between the parts, the rotation of the feed screw and the discharge amount are not synchronized, and there is a problem to be solved in that the supply becomes unstable.

The present invention has solved the problems existing in the prior art, and can supply molding materials (pellets, extenders) in various forms accurately and stably.
In addition, it is another object of the present invention to provide a material supply device for an injection molding machine that can accurately control a supply amount.

[0009]

The present invention relates to a material supply device 1 for an injection molding machine having a feed screw 4 for controlling a supply amount of a molding material M supplied from a hopper 2 into a heating cylinder 3. At the time of construction, a sleeve member 7 whose front end is closed by a closing portion 6 is inserted between a material supply passage 5 accommodating the feed screw 4 and the feed screw 4, and a center 7o of the sleeve member 7 is provided.
A discharge window 8 for discharging the molding material M is provided on a peripheral surface 7 s of the sleeve member 7 which is located obliquely above and near the closing portion 6.

In this case, according to a preferred embodiment, the discharge window 8 has the outside facing the material drop passage 9 communicating with the inside of the heating cylinder 3 and the inside directly facing the flight portion 4L of the feed screw 4. . The discharge window 8 may be provided on the side where the rotational movement direction R of the feed screw 4 is upward, and may be provided at a position where the circumferential angle Q from a horizontal line passing through the center 7o of the sleeve member 7 is approximately 45 °. desirable. Further, the sleeve member 7 can be provided detachably with respect to the material supply passage 5.

As a result, the material discharge side of the material supply passage 5 in which the feed screw 4 is accommodated is closed by the closing portion 6 and the sleeve member 7. When an expanding material smaller than a general pellet, such as a glass balloon or a glass bead, is used as the molding material M, the molding material M is sent forward by the flight section 4L of the feed screw 4. At the same time, the material is discharged from the discharge window 8 to the material falling passage 9. At this time, the discharge window 8 is connected to the sleeve member 7.
Is located on the peripheral surface 7s of the sleeve member 7, which is located obliquely above the center 7o and near the closing portion 6, so that the discharge window 8 can directly face the flight portion 4L.
Therefore, the molding material M is discharged from the flight section 4L.
In addition to the stable operation in synchronization with the rotation of the feed screw 4, the discharge of the molding material M is immediately stopped by the stop of the feed screw 4, and the supply amount is accurately controlled.

[0012]

Next, preferred embodiments according to the present invention will be described in detail with reference to the drawings.

First, an overall schematic configuration of an injection molding machine A including the material supply device 1 according to the present embodiment will be described with reference to FIG.

The injection molding machine A comprises an unillustrated mold clamping device having an injection device 10 and a mold 11. The injection device 10 includes a heating cylinder 3 in which an injection screw 12 is inserted. The heating cylinder 3 has an injection nozzle 13 at the front end, and rotates and moves the injection screw 12 at the rear end of the heating cylinder 3. A screw drive 14 is provided.

At the rear of the heating cylinder 3, there is provided a pellet supply device 15 for supplying pellets as a resin material.
The pellet supply device 15 includes a device block 16. At the upper end of the device block 16, a hopper 17 for storing pellets is provided, and a horizontal material supply passage 18 is provided inside the device block 16. This material supply passage 18
The material intake side communicates with the drop port 17s of the hopper 17, and the material discharge side of the material supply passage 18 communicates with the device block 16.
Communicates with a material drop passage 19 provided in the inside. The material drop passage 19 communicates with the inside of the heating cylinder 3. Further, a feed screw 20 is provided inside the material supply passage 18.
And the side of the device block 16 is connected to the end of the feed screw 20 so that the feed screw 2
0 is provided.

Accordingly, the material supply passage 18 from the hopper 17
The pellets supplied to the heating cylinder 3 are transported by the feed screw 20 rotated by the drive motor unit 21 and fall through the material drop passage 19 to be supplied to the inside of the heating cylinder 3. In this case, the supply amount of the pellets is variably controlled by the rotation speed of the drive motor unit 21.

On the other hand, the material supply device 1 according to the present embodiment is disposed at an intermediate portion of the heating cylinder 3, preferably at a substantially central portion.

Next, the structure of the material supply device 1 will be specifically described with reference to FIGS.

The material supply device 1 is basically constructed in the same manner as the above-mentioned pellet supply device 15. 1 is provided with a hopper 2 for accommodating a molding material (expanding material) M at the upper end of the device block 23, and a horizontal material supply passage 5 is provided inside the device block 23. Provide. The material intake side of the material supply passage 5 communicates with the drop port 2s of the hopper 2, and the material discharge side of the material supply passage 5 communicates with the material fall passage 9 provided inside the device block 23. The material drop passage 9 communicates with the inside of the heating cylinder 3. Further, the feed screw 4 is accommodated in the material supply passage 5, and a drive motor unit 25 that is connected to an end of the feed screw 4 and drives the feed screw 4 to rotate is disposed on one side of the device block 23. Set up.

On the other hand, a rotation detecting mechanism is provided on the other side of the device block 23. In the figure, reference numeral 28 denotes a rotation detecting rod in the rotation detecting mechanism. This rotation detecting rod 28 is connected to a supported shaft 4 a provided at the tip of the feed screw 4 and having a smaller diameter than the feed screw 4. Reference numeral 26 denotes the supported shaft 4a and the rotation detecting rod 2.
8 are the accommodation holes.

Then, the closing portion 6 is inserted into the accommodation hole 26. The closing part 6 is detachable from the accommodation hole 26. The closing part 6 is formed in a cylindrical shape, and the supported shaft 4a passes through a bearing part 27 provided at the center.

A sleeve member 7 is inserted between the material supply passage 5 and the feed screw 4. Sleeve member 7
Is formed in a cylindrical shape as shown in FIGS. 2 to 4, a discharge window 8 for discharging the molding material M is provided at a front portion of the peripheral surface 7s, and an upper half portion is cut off at a rear portion of the peripheral surface 7s. A through hole 29 for the molding material M is provided. Thereby, when the sleeve member 7 is inserted between the material supply passage 5 and the feed screw 4, the front end of the sleeve member 7 fits into the convex portion 6 p provided on the end face of the closing portion 6 and is closed. , Through hole 29
Is located between the falling port 2s and the material supply passage 5.

Further, the discharge window 8 is provided obliquely above the center 7o of the sleeve member 7. That is, as shown in FIG. 3, the feed screw 4 is provided at a position where the rotational movement direction R of the feed screw 4 is the upward direction and the circumferential angle Q from the horizontal line passing through the center 7o is approximately 45 °, and the feed screw 4 is closed. It is arranged near the part 6. In addition, the shape of the discharge window 8 is formed in a horizontally long rectangle. The discharge window 8 has the outside facing the material drop passage 9 and the inside facing the flight part 4L of the feed screw 4 directly. This sleeve member 7 is detachable from the material supply passage 5.

In the case of a vent-type injection molding machine, since a vent hole for discharging steam and gas components generated from the molten resin to the outside is provided at an intermediate portion of the heating cylinder 3, the vent hole is directly used to make a material. The supply device 1 can be mounted.
Therefore, by communicating the upper part of the material drop passage 9 in the material supply device 1 with the atmosphere, the function of the vent hole can be shared.

Next, the overall operation of the injection molding machine A including the operation of the material supply device 1 according to this embodiment will be described with reference to FIGS.
This will be described with reference to FIG.

First, the molding material M is stored in the hopper 2. The molding material M uses a glass balloon (or a glass bead). Glass balloons have a diameter of 0.03 ~
It is an internal hollow granular sphere of about 0.06 mm. If such a glass balloon is directly filled in the resin, it functions as a filler for reducing the weight of the molded product.

When the feed screw 4 is rotated by the drive motor unit 25, the molding material M supplied from the hopper 2 is sent forward by the flight portion 4L of the feed screw 4, and the material M falls from the discharge window 8. It is discharged to the passage 9. At this time, the discharge window 8 is connected to the sleeve member 7.
Is located diagonally above and in the vicinity of the closing portion 6 with respect to the center 7o of the airbag, and the flight portion 4L directly faces the discharge window 8, so that the discharge amount (supply amount) of the molding material M depends on the rotation of the flight portion 4L. Synchronously, it is always constant, and the supply is performed stably. In addition, since the discharge window 8 exists on the side where the rotational movement direction R of the feed screw 4 is upward, the molding material M is scraped up from below the discharge window 8 and discharged. Therefore, when the feed screw 4 stops, the discharge of the molding material M also stops immediately, and the supply amount is accurately controlled.

On the other hand, the pellets are supplied from the pellet supply device 15 into the heating cylinder 3, heated and melted in the heating cylinder 3, and transferred forward by the injection screw 12. Then, the molding material M is supplied from the above-described material supply device 1 into the molten resin, and is mixed into the molten resin. The molten resin mixed with the molding material M reaches the front of the heating cylinder 3 and is injected and filled into the mold 11 from the injection nozzle 13.

In the case of using general pellets in the material supply device 1, the closing portion 6 and the sleeve member 7 may be removed. Accordingly, the pellet supply device 1 can be used as it is, and for example, two-color molding can be performed by combining with the pellet supplied from the pellet supply device 15.

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment.
For example, the sleeve member and the closing portion may be integrated, or the sleeve member and the closing portion may be provided in a non-detachable manner with respect to the device block. In addition, the configuration, shape, formation position, quantity, numerical value, and the like of the details can be arbitrarily changed without departing from the gist of the present invention.

[0031]

As described above, in the material supply device of the injection molding machine according to the present invention, the sleeve member whose front end is closed by the closing portion is inserted between the material supply passage accommodating the feed screw and the feed screw. In addition, since a discharge window for discharging the molding material is provided on the peripheral surface of the sleeve member, which is located obliquely above the center of the sleeve member and near the closed portion, the following remarkable effects are obtained. .

In addition to being able to accurately supply various forms of molding material (pellets, fillers), the molding material is discharged in synchronization with the rotation of the flight section of the feed screw, so that the molding material can be supplied stably.

Since the discharge of the molding material is immediately stopped by the stop of the feed screw, accurate control of the supply amount can be performed.

[Brief description of the drawings]

FIG. 1 is a sectional side view of a main part of a material supply device according to the present invention,

FIG. 2 is a partially cutaway side view of a sleeve member in the material supply device.

FIG. 3 is a cross-sectional front view including a discharge window and a feed screw of a sleeve member in the material supply device;

FIG. 4 is a perspective view showing a part of a sleeve member in the material supply device.

FIG. 5 is a partial cross-sectional side view of an injection molding machine including the material supply device;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Material supply apparatus 2 Hopper 3 Heating cylinder 4 Feed screw 4L Flight part 5 Material supply passage 6 Closure part 7 Sleeve member 7o Center of sleeve member 7s Sleeve member peripheral surface 8 Discharge window 9 Material drop passage M Molding material R Molding direction R Q Circumferential angle

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-329114 (JP, A) JP-A-62-132624 (JP, A) JP-A-48-62855 (JP, A) Jpn. 46766 (JP, U) JP-A 56-140417 (JP, U) JP-A 63-148409 (JP, U) Registered utility model 3017542 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , (DB name) B29C 45/00-45/24

Claims (5)

(57) [Claims] 1. A material supply device for an injection molding machine having a feed screw for controlling a supply amount of a molding material supplied from a hopper into a heating cylinder, between a material supply passage accommodating the feed screw and the feed screw. ,
A discharge window for inserting the sleeve member whose front end is closed by the closing portion, and discharging the molding material to a peripheral surface of the sleeve member located obliquely above the center of the sleeve member and near the closing portion. A material supply device for an injection molding machine, comprising: 2. The injection device according to claim 1, wherein the discharge window has an outside facing a material drop passage communicating with the inside of the heating cylinder and an inside facing directly to a flight portion of the feed screw. Material supply device for molding machines. 3. The material supply device for an injection molding machine according to claim 1, wherein the discharge window is provided on a side where a rotational movement direction of the feed screw is an upward direction. 4. The material for an injection molding machine according to claim 1, wherein the discharge window is provided at a position where a circumferential angle from a horizontal line passing through the center of the sleeve member is approximately 45 °. Feeding device. 5. A material supply device for an injection molding machine according to claim 1, wherein said sleeve member is detachable from said material supply passage.